Recombinant DNA technology is now being applied to industrial production processes. One method of producing products (such as proteins) using this technology is to cleave a cloning vector (e.g. a plasmid) to provide a linear DNA having ligatable termini. A gene which codes for the product to be produced (and having complementary termini) is then inserted into the vector to provide a biologically functional replicon with the desired phenotypical property. The replicon can then be inserted into a host cell (e.g. bacteria) by a process called transformation. Isolation of the transformants provides cells for replication and expression of the foreign DNA molecules. See e.g. U.S. Pat. No. 4,237,224 issued to Cohen, et al. on Dec. 2, 1980; T. Tanaka & B. Weisblum, Construction Of A Colicin E1-R Factor Composite Plasmid In Vitro: Means For Amplification Of Deoxyriboneucleic Acid, Volume 121, No. 1, J. Bacteriol. pp. 354-362 (1975) (The disclosure of this article and of all other articles referred to below are incorporated herein by reference as if fully set forth below). See also U.S. Pat. No. 4,338,397 Gilbert et al. issued July 6, 1982 for definitions of words commonly used in recombinant DNA technology.
However, it has been found that certain of the products specified by cloned genes inhibit the growth of the host cells. This inhibition results in a lower than desirable yield of the product which is produced by the cells. Examples of products which have shown this type of inhibitory effect are interferon and certain viral capsid proteins. In light of the importance of decreasing the cost of certain of these products, it can readily be appreciated that a need exists for a method of improving the yields of organisms that produce products where the products inhibit the organisim's reproduction.